1. Field of the Invention
The present invention relates to methods of manufacturing roofing products.
2. Description of Related Art
Traditional roofing products include asphalt shingles, wood shakes, slates, and metal panels. Each of these products has benefits. For instance, wood shakes and slate roofing are very aesthetic. However, wood shakes are considered a fire hazard and slate is very expensive and subject to cracking.
Less expensive roofing products have been introduced to simulate wood shakes and slate roofing. Some asphalt shingles have been developed that resemble slate or shake roofing. However, asphalt products typically do not have the structural rigidity of slate or shake. Metal and plastic shingles have been developed that simulate shake and slate. However, those products are subject to denting and breakage.
Composite roofing products, typically composed of at least a polymer and a filler component, have been developed to resemble certain of the more traditional roofing products, including shakes and slates. The manufacture of these composite roofing products has traditionally involved the use of extrusion, pressing, and/or molding techniques. An example of a process involving extrusion of roofing products composed primarily of asphalt appears in U.S. Pat. No. 5,690,876. Examples of molding processes used in making composite roofing products include those in U.S. Pat. Nos. 6,025,052; 6,112,492; and 5,635,124. The use of both extrusion and molding is disclosed in U.S. Pat. No. 6,290,885.
Some of these patents promote economies of scale in aspects of their manufacturing. However, none discloses a manufacturing solution that takes advantages of economies of scale and may be automated from virtually beginning to end.